/* 下拉菜单 hover 显隐 */
.dropdown .dropdown-menu {
    display: none;
}
.dropdown:hover .dropdown-menu {
    display: block;
}

/* Banner 全终端自适应 */
.carousel-item {
    opacity: 0;
    transition: opacity 0.8s ease;
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;
    background-attachment: scroll;
    background-color: rgba(0, 0, 0, 0.3);
    background-blend-mode: multiply;
}
.carousel-item.active {
    opacity: 1;
}

/* 轮播按钮 hover 效果 */
.car-btn:hover {
    background-color: rgba(0, 0, 0, 0.5);
}

/* 导航栏滚动/悬浮变白样式 */
header.white {
    background-color: #ffffff;
}
header.white .logo,
header.white .nav-list a {
    color: #333333;
}
header.white .menu-btn span {
    background-color: #333333;
}

/* 背景图定位：居中底部 */
.bg-center-bottom {
    background-position: center bottom;
    background-size: contain;
}
/* 数字动画基础样式 */
.num {
    transition: all 0.2s ease;
}